Sucking is one of the natural reflexes that babies have. According to the American Academy of Pediatrics, all infants are born with an intense need to suck. In fact, they start sucking their thumb or their other fingers while still in the womb (you may even witness them doing this during an ultrasound). This ability is necessary for newborn babies to procure milk without having to be taught.Apart from this, sucking on thumbs, fingers and other objects such as pacifiers enable babies or young children to feel secure in his or her surroundings. It helps them learn about the world. Sucking keeps them calm and relaxed and even helps them go to sleep. | Dr.Mitch V. Mendoza